Fuze function selection and firing system

ABSTRACT

1. In a selective multi-mode fuze firing circuit for a missile: A. A SELECT VOLTAGE INPUT TERMINAL MEANS FOR ACCEPTING ANY ONE OF THREE SELECT VOLTAGES FOR SELECTING ANY ONE OF PROXIMITY, IMPACT-INSTANTANEOUS AND IMPACT-DELAY MODES OF OPERATION, B. A FUZE VOLTAGE SUPPLY INPUT, C. A PROXIMITY SIGNAL INPUT, D. AN INSTANTANEOUS DETONATION MEANS, E. A DELAY DETONATION MEANS, F. AN IMPACT FUZING MEANS, G. A TWO-POSITION THREE-SECTION SWITCH MEANS, H. FIRST AND SECOND FUSE LINKS, I. A GAS DIODE WHICH WILL IGNITE IN EITHER DIRECTION AT A SPECIFIC POTENTIAL, J. A FIRING CAPACITOR, K. THE FIRST SECTION BEING CLOSED TO GROUND AND THE SECOND AND THIRD SECTIONS BEING OPEN IN THE FIRST POSITION OF SAID THREESECTION SWITCH MEANS, L. FIRST AND SECOND CHARGING RESISTORS, M. ONE SIDE OF EACH OF SAID FUSE LINKS, FIRING CAPACITOR AND ONE SIDE OF THE THIRD SECTION OF SAID THREE-SECTION SWITCH MEANS BEING CONNECTED TO THE SELECT VOLTAGE INPUT TERMINAL THROUGH SAID FIRST CHARGING RESISTOR, N. SAID DELAY DETONATION MEANS BEING CONNECTED BETWEEN THE OTHER SIDE OF THE THIRD SECTION OF SAID THREE-SECTION SWITCH MEANS AND GROUND, O. FIRST AND SECOND DIODE RECTIFIERS, P. FIRST AND SECOND BLEEDER RESISTORS EACH CONNECTED TO A RESPECTIVE OPPOSITE SIDE OF SAID FIRING CAPACITOR, Q. THE OTHER SIDE OF SAID FIRST FUSE LINK BEING CONNECTED TO SAID PROXIMITY SIGNAL INPUT, THE CATHODE OF SAID DIODE RECTIFIER AND ONE SIDE OF SAID GAS DIODE; THE OTHER SIDE OF SAID GAS DIODE BEING CONNECTED TO GROUND, R. THE OTHER SIDE OF SAID SECOND FUSE LINK BEING CONNECTED TO THE ANODE OF SAID DIODE RECTIFIER AND ONE SIDE OF THE SECOND SECTION OF SAID THREE-SECTION SWITCH MEANS, S. SAID INSTANT DETONATION MEANS BEING CONNECTED BETWEEN THE OTHER SIDE OF THE SECOND SECTION OF SAID THREE-SECTION SWITCH MEANS AND GROUND, T. SAID IMPACT FUSING MEANS BEING CONNECTED BETWEEN THE OTHER SIDE OF SAID FIRING CAPACITOR AND GROUND, U. ONE SIDE OF THE FIRST SECTION OF SAID THREE-SECTION SWITCH MEANS BEING CONNECTED TO THE CATHODE OF SAID SECOND DIODE RECTIFIER, V. THE OTHER SIDE OF THE FIRST SECTION OF SAID THREE-SECTION SWITCH MEANS BEING CONNECTED TO THE OTHER SIDE OF SAID FIRING CAPACITOR FOR CONNECTING SAID CAPACITOR TO GROUND WHEN THE SWITCH MEANS IS IN A FIRST POSITION AND TO THE CATHODE OF SAID SECOND DIODE RECTIFIER WHEN IN ITS SECOND POSITION, W. SAID SECOND CHARGING RESISTOR BEING CONNECTED BETWEEN THE ANODE OF SAID SECOND RECTIFIER AND SAID FUZE VOLTAGE SUPPLY INPUT, X. WHEREBY EACH OF ANY OF SAID THREE SELECT VOLTAGES APPLIED TO SAID SELECT VOLTAGE INPUT TERMINAL WILL SELECT A PARTICULAR ONE OF ANY OF PROXIMITY, IMPACT-DELAY AND IMPACT-INSTANTANEOUS MODES OF OPERATION.

United States Patent [191 Lunt et al.

[ FUZE FUNCTION SELECTION AND FIRING SYSTEM Inventors: Wilbur B. Lunt, Arlington; Maurice H. Brown, Riverside, both of Calif.

Primary Examiner-Benjamin A. Borchelt Assistant ExaminerThomas H. Webb Attorney-Q. Baxter Warner and J. M. St. Amand EXEMPLARY CLAIM I. In a selective multi-mode fuze firing circuit for a missile:

a. a select voltage input terminal means for accepting any one of three select voltages for selecting any one of proximity, impact-instantaneous and impact-delay modes of operation,

b. a fuze voltage supply input,

c. a proximity signal input,

d. an instantaneous detonation means,

e. a delay detonation means,

f. an impact fuzing means,

g. a two-position three-section switch means,

h. first and second fuse links,

i. a gas diode which will ignite in either direction at a specific potential,

j. a firing capacitor,

k. the first section being closed to ground and the second and third sections being open in the first position of said three-section switch means,

1. first and second charging resistors,

VOLTAGE [111 3,722,416 [451 Mar. 27, 1973 m. one side of each of said fuse links, firing capacitor and one side of the third section of said threesecu'on switch means being connected to the select voltage input terminal through said first charging resistor,

n. said delay detonation means being connected between the other side of the third section of said three-section switch means and ground,

0. first and second diode rectifiers,

p. first and second bleeder resistors each connected to a respective opposite side of said firing capacitor,

q. the other side of said first fuse link being connected to said proximity signal input, the cathode of said diode rectifier and one side of said gas diode; the other side of said gas diode being connected to ground,

. the other side of said second fuse link being connected to the anode of said diode rectifier and one side of the second section of said three-section switch means,

. said instant detonation means being connected between the other side of the second section of said three-section switch means and ground,

said impact fusing means being connected between the other side of said firing capacitor and ground,

. one side of the first section of said three-section switch means being connected to the cathode of said second diode rectifier,

. the other side of the first section of said threesection switch means being connected to the other side of said firing capacitor for connecting said capacitor to ground when the switch means is in a first position and to the cathode of said second diode rectifier when in its second position,

w. said second charging resistor being connected between the anode of said second rectifier and said fuze voltage supply input,

x. whereby each of any of said three select voltages applied to said select voltage input terminal will select a particular one of any of proximity, impact-delay and impact-instantaneous modes of operation.

4 Claims, 1 Drawing Figure AIRCRAFT SELECT VOL AGE IN PROXIMITY IN fib l5:

INSTANT D LAY DETONArOR DETONATOR FUZE FUNCTION SELECTION AND FIRING SYSTEM The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to fuze systems and more particularly to a missile fuze circuit in which a plurality of functional modes such as proximity, impact instantaneous or impact delay may be selected by the pilot before the missile is launched from an aircraft or the like.

Many modern weapons in both the guided missile and free-fall bomb categories are designed for multimode operation in order that their tactical employment may be broadened. In a large family of weapons it is often required that each weapon be operable under conditions of either near-ground (air burst), surface (instantaneous at impact), or penetrating (delay after impact), etc. The operation mode is selected by the firing station according to the target under attack, this type weapon generally being aircraft launched with appropriate mode selection being made by the pilot. The present invention is for a simplified mode selection and firing system for general use in such weapons.

It is an object of the invention, therefore to provide a novel remote fuze function selection and firing system.

Another object of the invention is to provide a novel fuze function selection and firing circuit using fusable links for performing mode selection functions.

A further object of the invention is to provide a simplified fuze circuit for selecting any one of a plurality of weapon functional modes.

Other objects and many of the attendant advantages of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

The FIGURE of drawing is a circuit diagram of an embodiment of the invention.

The present system functions in two different phases: that of fuze function selection performed at the pilots discretion just prior to launching of the weapon, and weapon warhead initiation at target encounter. Either of the detonators shown in the FIGURE of drawing becomes the initial sensitive element of the warhead explosive train; the Delay Detonator is initiated instantly on receipt of a suitable electrical pulse but contains a pyrotechnic which delays its output for some established time.

For purposes of performing selection of the weapon functional mode, the aircraft is provided with a fuze function selection system. This system, which is not a part of the present invention, normally consists of an electrical supply which provides a multiplicity of outputs (AC at various frequencies and DC of both polarities at several different magnitudes), and control components which allow the selection of any output as desired and its delivery to the weapon as desired via an umbilical cable. For purposes of performing the selection functions in the circuit illustrated, the voltages employed of those available, for example, are plus 300, for impact delay, minus 300 for impact instantaneous and either zero or any other potential below 200 volts for proximity.

Selection by the pilot of the Proximity function applies zero volts (or any potential below 200 volts DC) to the system at input terminal 10. Resistor 11 establishes the maximum allowable current drain on the aircraft control set. Capacitor 12 charges to whatever voltage is applied but the gas diode 14, a commercially available item which will ignite in either direction at a threshold potential of 225 volts DC, does not ignite and the circuit remains entirely unchanged. At launch the aircraft connection (via an umbilical cable) is of course broken, and subsequently a Safety-Arming device (not shown) reverses the position of all switch sections 15a and 15b and 15c from that shown and capacitor 12 is recharged to the missile fuze supply 16 potential. Resistor 13 dissipates all charge from the capacitor during the time between missile launch and electrical arming. The recharge current is via the detonator bridges 18 and 19 and is kept well within safe limits by the charging resistor 20. Rectifier 21 prevents subsequent loss of charge in case of later power supply failure. Capacitor 12 now becomes the firing capacitor of the back-up impact fuzing switch 22; other means than impact switch 22 may be used for connecting terminal 23 to ground for impact fuzing at missile impact. Under appropriate action from a proximity fuze, for example, the system for which is not shown and which is not part of this invention, an electrical firing pulse will be delivered at Proximity In" terminal 17, thence to the two detonators l8 and 19 via the fuse links 24 and 25. In this case initiation of delay detonator 19 serves as a reliability backup, even though action of instantaneous detonator 18 is desired and will be obtained to a very high degree of reliability. In this firing action, fuse links 24 and 25 which have a resistance of a fraction of an ohm, are not blown since by far the greater part of the energy in the firing pulse is dissipated in the relatively high resistance of detonator bridges 18 and 19. In case of faulty action of the proximity fuze where it provides no firing pulse at terminal 17, ground impact will cause deformation and closure of impact switch 22 serving to discharge capacitor 12 through detonators 18 and 19 assuring their back-up initiation. A high-valued resistor 26 dissipates any charge remaining on the firing capacitor 12 following any circuit test or checkout.

If instead of Proximity function, the pilot had selected Impact Instantaneous" as the preferable mode of operation against a target relatively invulnerable to an airburst, his selection system would have delivered minus 300 volts DC to the missile at input 10. Capacitor 12 would start to charge to the minus 300 volt level. But since its potential also appears across gas diode 14, at the 225 volt threshold firing potential of the diode the tube would ignite and discharge the capacitor through fuse link 24. Since at ignition the resistance of gas diode 14 drops to a very low value, the resulting high current literally explodes fuse link 24 and effectively opens its circuit. With a negative potential on capacitor 12 the rectifier 27 prevents the similar removal of fuse link 25. After missile launching, the closure of all switch sections 15a, 15b and 15c, and the recharging of capacitor 12 by the missile fuze supply 16, it is seen that removal of fuse link 24 has effectively blocked out any positive signal at terminal 17 from the proximity fuze since its positive output pulse is blocked by rectifier 27. (If a negative signal is used at terminal 17 then diode 27 should be reversed and a plus 300 volts would be required for Impact Instantaneous" selection.) Then at ground impact the action of impact switch 22 serves to discharge capacitor 12 through detonation means 18 and 19, achieving instant warhead action by instant detonator means 18 and again backed up by delay detonator means 19.

If the pilot had chosen to select an Impact Delay mode of operation in order to achieve target penetration prior to warhead detonation, plus 300 volts DC would have been delivered to the weapon at terminal 10. Again capacitor 12 would charge to the 225 volts DC ignition potential of gas diode 14, but this time on diode ignition the discharge of capacitor 12 would remove both fuze links 24 and 25 since rectifier 27 now allows fuse link 25 circuit conduction. Then at target encounter not only is the positive signal at terminal 17 from the proximity fuze again blocked but the discharge of the recharged capacitor 12 by closure of impact switch 22 is now limited to the delay detonator l9 circuit, as was desired. (Again, if a negative signal is 17 diode 27 should be reversed and a minus 300 volts would be required for Impact Delay selection.)

The available fuze voltage for use in impact fuze action primarily determines many of the circuit component ratings and values. If, for example, the fuzing voltage was 50 volts, the gas diode chosen could be a type having an ignition threshold of (say) 100 volts and the aircraft-available voltages of plus 195 and minus 195 could then be used for Impact Instantaneous and Impact Delay selection, with zero (or any potential below approximately 80 volts DC) being used as the input for Proximity selection. This would also lower the voltage rating requirements of capacitor 12, which must be able to withstand the highest voltage possible of application in this case 195 volts. (In the previous description for the FIGURE of drawing capacitor 12 must have had a voltage rating of minimum 300 volts DC.) However, if these lower voltages are used, the capacity of capacitor 12 would most probably have to be raised in order to insure the availability of sufficient pulsed energy to reliably remove fuse links 24 and 25 from the circuit when the Impact Delay mode of operation is selected. Indeed, the diameters of the platinum wire, for example, used for link 24 and link 25 (platinum is recommended because of its handling strength, though here too other choices are available if described) may well need reduction in order that reliability of their removal be obtained with the lower peak currents available.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a selective muIti-mode fuze firing circuit for a missile:

a. a select voltage input terminal means for accepting any one of three select voltages for selecting any one of proximity, impact-instantaneous and impact-delay modes of operation,

b. a fuze voltage supply input,

0. a proximity signal input,

d. an instantaneous detonation means,

e. a delay detonation means,

f. an impact fuzing means,

g. a two-position three-selection switch means,

h. first and second fuse links,

i. a gas diode which will ignite in either direction at a specific potential,

j. a firing capacitor,

k. the first section being closed to ground and the second and third sections being open in the first position of said three-section switch means,

1. first and second charging resistors,

m. one side of each of said fuse links, firing capacitor and one side of the third section of said three-section switch means being connected to the select voltage input terminal through said first charging resistor,

. said delay detonation means being connected between the other side of the third section of said three-section switch means and ground,

. first and second diode rectifiers,

. first and second bleeder resistors each connected to a respective opposite side of said firing capacitOl',

. the other side of said first fuse link being connected to said proximity signal input, the cathode of said diode rectifier and one side of said gas diode; the other side of said gas diode being connected to ground,

r. the other side of said second fuse link being connected to the anode of said diode rectifier and one side of the second section of said three-section switch means,

5. said instant detonation means being connected between the other side of the second section of said three-section switch means and ground,

t. said impact fusing means being connected between the other side of said firing capacitor and ground,

. one side of the first section of said three-section switch means being connected to the cathode of said second diode rectifier,

. the other side of the first section of said three-section switch means being connected to the other side of said firing capacitor for connecting said capacitor to ground when the switch means is in a first position and to the cathode of said second diode rectifier when in its second position,

w. said second charging resistor being connected between the anode of said second rectifier and said fuze voltage supply input,

x. whereby each of any of said three select voltages applied to said select voltage input terminal will select a particular one of any of proximity, impactdelay and impact-instantaneous modes of operation.

2. A circuit as in claim 1 wherein the values of the three select voltages being for the first, from 0 to any potential below the specific potential of said gas diode, the second, a positive potential greater than the specific potential of said gas diode, and third, a negative potential greater than the specific potential of said gas diode, the voltage rating of said firing capacitor being such as to withstand the highest of said three select voltages.

3. A circuit as in claim 1 wherein said second charging resistor operates to keep the charging current within safe limits below that required to detonate either of said detonation means.

4. A selective multi-mode fuze firing system comprising:

a. a means for accepting any one of three voltages for selecting any one of three modes of operation,

b. a fuze voltage supply input,

c. a proximity signal input,

(1. moderate-energy instantaneous and delay detonation means,

e. an impact fusing means,

f. a firing capacitor for two phase operation,

g. a gas diode which conducts in either direction at a specified potential,

h. low-resistance first and second fuse links which operate to perform select functions,

i. a two-position three-section switch means,

j. a firing capacitor,

k. the values of the three select voltages being for the first, from 0 to any potential below the specified ignition potential of said gas diode, the second, a positive potential greater than the specified potential of said gas diode, and third, a negative potential greater than the specified potential of said gas diode, said firing capacitor having a non-polar voltage rating such as to withstand the highest of said three select voltages,

I. one side of each of said fuse links, firing capacitor and one side of the third section of said three-section switch means being connected to the select voltage input terminal,

m. said delay detonation means being connected between the other side of other side of the third section of said three-section switch means and ground,

11. first and second diode rectifiers,

o. first and second bleeder resistors each connected to a respective opposite side of said firing capacitor,

p. the other side of said first fuse link being connected to said proximity signal input, the cathode of said diode rectifier and one side of said gas diode; the other side of said gas diode being connected to ground,

q. the other side of said second fuse link being connected to the anode of said diode rectifier and one side of the second section of said three-section switch means,

r. said instant detonation means being connected between the other side of the second section of said three-section switch means and ground,

5. said impact fusing means being connected between the other side of said firing capacitor and ground,

t. one side of the first section of said three-section switch means being connected to the cathode of said second diode rectifier,

u. the other side of the first section of said three-section switch means being connected to the other side of said firing capacitor for connecting said capacitor to ground when the switch means is in a first position and to the cathode of said second diode rectifier when in its second position,

v. said second charging resistor being connected between the anode of said second rectifier and said fuze voltage supply input,

w. whereby each of said three select voltages applied to said select voltage input terminal will select a particular mode of operation. 

1. In a selective multi-mode fuze firing circuit for a missile: a. a select voltage input terminal means for accepting any one of three select voltages for selecting any one of proximity, impact-instantaneous and impact-delay modes of operation, b. a fuze voltage supply input, c. a proximity signal input, d. an instantaneous detonation means, e. a delay detonation means, f. an impact fuzing means, g. a two-position three-selection switch means, h. first and second fuse links, i. a gas diode which will ignite in either direction at a specific potential, j. a firing capacitor, k. the first section being closed to ground and the second and third sections being open in the first position of said threesection switch means, l. first and second charging resistors, m. one side of each of said fuse links, firing capacitor and one side of the third section of said three-section switch means being connected to the select voltage input terminal through said first charging resistor, n. said delay detonation means being connected between the other side of the third section of said three-section switch means and ground, o. first and second diode rectifiers, p. first and second bleeder resistors each connected to a respective opposite side of said firing capacitor, q. the other side of said first fuse link being connected to said proximity signal input, the cathode of said diode rectifier and one side of said gas diode; the other side of said gas diode being connected to ground, r. the other side of said second fuse link being connected to the anode of said diode rectifier and one side of the second section of said three-section switch means, s. said instant detonation means being connected between the other side of the second section of said three-section switch means and ground, t. said impact fusing means being connected between the other side of said firing capacitor and ground, u. one side of the first section of said three-section switch means being connected to the cathode of said second diode rectifier, v. the other side of the first section of said three-section switch means being connected to the other side of said firing capacitor for connecting said capacitor to ground when the switch means is in a first position and to the cathode of said second diode rectifier when in its second position, w. said second charging resistor being connected between the anode of said second rectifier and said fuze voltage supply input, x. whereby each of any of said three select voltages applied to said select voltage input terminal will select a particular one of any of proximity, impact-delay and impact-instantaNeous modes of operation.
 2. A circuit as in claim 1 wherein the values of the three select voltages being for the first, from 0 to any potential below the specific potential of said gas diode, the second, a positive potential greater than the specific potential of said gas diode, and third, a negative potential greater than the specific potential of said gas diode, the voltage rating of said firing capacitor being such as to withstand the highest of said three select voltages.
 3. A circuit as in claim 1 wherein said second charging resistor operates to keep the charging current within safe limits below that required to detonate either of said detonation means.
 4. A selective multi-mode fuze firing system comprising: a. a means for accepting any one of three voltages for selecting any one of three modes of operation, b. a fuze voltage supply input, c. a proximity signal input, d. moderate-energy instantaneous and delay detonation means, e. an impact fusing means, f. a firing capacitor for two phase operation, g. a gas diode which conducts in either direction at a specified potential, h. low-resistance first and second fuse links which operate to perform select functions, i. a two-position three-section switch means, j. a firing capacitor, k. the values of the three select voltages being for the first, from 0 to any potential below the specified ignition potential of said gas diode, the second, a positive potential greater than the specified potential of said gas diode, and third, a negative potential greater than the specified potential of said gas diode, said firing capacitor having a non-polar voltage rating such as to withstand the highest of said three select voltages, l. one side of each of said fuse links, firing capacitor and one side of the third section of said three-section switch means being connected to the select voltage input terminal, m. said delay detonation means being connected between the other side of other side of the third section of said three-section switch means and ground, n. first and second diode rectifiers, o. first and second bleeder resistors each connected to a respective opposite side of said firing capacitor, p. the other side of said first fuse link being connected to said proximity signal input, the cathode of said diode rectifier and one side of said gas diode; the other side of said gas diode being connected to ground, q. the other side of said second fuse link being connected to the anode of said diode rectifier and one side of the second section of said three-section switch means, r. said instant detonation means being connected between the other side of the second section of said three-section switch means and ground, s. said impact fusing means being connected between the other side of said firing capacitor and ground, t. one side of the first section of said three-section switch means being connected to the cathode of said second diode rectifier, u. the other side of the first section of said three-section switch means being connected to the other side of said firing capacitor for connecting said capacitor to ground when the switch means is in a first position and to the cathode of said second diode rectifier when in its second position, v. said second charging resistor being connected between the anode of said second rectifier and said fuze voltage supply input, w. whereby each of said three select voltages applied to said select voltage input terminal will select a particular mode of operation. 